Tap, tap, tap... I know what auction you're talking about. An interesting point that I don't think you mentioned is that in the 1st auction the buyer and seller were both from Nottingham, so it doesn't make sense that buyer wanted the bike posted.
Obviously he wanted more money for it, hence no second chance offer. And the private lisiting, so the shill bidding is less obvious this time. I also notice that your high bid in the 1st auction was £80, and suspiciously the rival bidder in the new auction bid £79 to take it right up to your max last time.
It could be that a genuine (newish) bidder done his homework on you course... but I doubt it. Given all the information I would have withdraw my bid, but with less than an hour to go you can't now anyway. It's still a good price though!